1. Field of the Invention
The invention relates to a device for transporting printed products placed in a stack onto a support and supplied to a conveying device, arranged downstream of the support in a conveying-effecting manner and comprising a traction means circulating about at least two deflecting rollers, by means of a reversible pushing device acting on the back side of the stack.
2. Description of the Related Art
Devices of this kind are employed inter alia for stacking printed products or finished printed products such as, for example, newspapers, magazines, brochures or the like, which are subsequently enveloped with a foil or tied with a string or with a strap.
In this connection, so-called stackers available from the company Mxc3xcller Martini Marketing AG are known under the name xe2x80x9cFortexe2x80x9d, xe2x80x9cPracticoxe2x80x9d or xe2x80x9cRapidoxe2x80x9d.
The stacks, which are pushed out of the stacking area at high speed and are comprised of loosely stacked printed products, are subjected during their transport to the next processing station to various effects which can change the stack formation so that they can no longer be processed in a satisfactory or a sufficient way.
It is an object of the present invention to provide a device of the aforementioned kind with which the stack of printed products can be transported while maintaining the formation in a reliable way and at least approximately with constant format.
In accordance with the present invention, this is achieved in that the traction means at least at the upstream end is positioned approximately at the level of the support and forms a conveying plane together with a substantially horizontal guide table that adjoins on both ends. With this measure, a stack which is formed of loosely placed printed products can be transferred with uniform speed deceleration into a subsequent processing station so that the printed products do not experience displacement relative to one another. In this connection, the conveying plane can deviate from a planar surface, for example, it can be curved.
For beneficial effects in regard to the conveying action by the traction means, the guide table is positioned with a step relative to the support.
In order for the stack to remain substantially unchanged during transport, the conveying device is configured as a support device accompanying the leading or front end of the stack along the conveying path.
When the traction means has a conveying direction slanted toward the end of the conveying path, the conveying action can be further optimized.
For a universal use of the conveying device, it is favorable when the spacing between the pushing device and the support device can be adjusted depending on the format of the printed products.
For this purpose, the support device is advantageously driven in a cycle-synchronized fashion with the pushing device such that the stack during transfer to the conveying device is arranged between the pushing device and the support device so that a movement of the printed products within the stack can be prevented.
In this connection it is especially advantageous when the support device is formed by a vertical support strip acting onto the leading lateral edge of the stack, respectively.
For laterally guiding the stack in the conveying direction, the support strips are preferably fastened on at least one traction member forming lateral guide walls or guide sections and circulating about vertical axes.
For the adaptation to the format size of the printed products of the stack, the guide walls are arranged to be adjustable transversely to the conveying direction.
For changing the conveying action and conveying length of the conveying device, it is expedient when the slant of the conveying-effecting area of the traction means is adjustable about a horizontal axis extending transversely to the conveying direction of the stack.
An advantageous change of the conveying action can be obtained when the guide table is configured to be height-adjustable.
Preferably, the support is arranged on a table of a stacking device or a stacker and the printed products project in the conveying direction laterally past the support so that within the lower stack area they are slanted downwardly toward the table.
Expediently, the drive device of the conveying device is connected with a control device so that the conveying speed of the stack can be decelerated or controlled.
In the following, the invention will be described by means of one embodiment with the aid of the drawing, reference being had to the drawing with regard to all details not disclosed particularly in the description.